Self-assembly is a powerful method to obtain large discrete functional molecular architectures. When using a single building block, self-assembly generally yields symmetrical objects in which all the subunits relate similarly to their neighbours. Here we report the discovery of a family of self-constructing cyclic macromolecules with stable folded conformations of low symmetry, which include some with a prime number (13, 17 and 23) of units, despite being formed from a single component. The formation of these objects amounts to the production of polymers with a perfectly uniform length. Design rules for the spontaneous emergence of such macromolecules include endowing monomers with a strong potential for non-covalent interactions that remain frustrated in competing entropically favoured yet conformationally restrained smaller cycles. The process can also be templated by a guest molecule that itself has an asymmetrical structure, which paves the way to molecular imprinting techniques at the level of single polymer chains.

自组装是获得大型离散功能分子结构的有效方法。当使用单个构建块时，自组装通常会产生对称对象，其中所有子单元都与其邻居类似。在这里，我们报告发现了一系列具有低对称性的稳定折叠构象的自构建环状大分子，其中包括一些具有素数（13、17 和 23）单元的分子，尽管它们是由单个组件形成的。这些物体的形成相当于生产具有完全均匀长度的聚合物。这种大分子自发出现的设计规则包括赋予单体强大的非共价相互作用潜力，这些相互作用在竞争熵有利但构象受限的较小循环中仍然受挫。